OpenVPN Server Setup Script

This script automates the process of setting up an OpenVPN server on a VPS running Ubuntu/Debian. It handles the installation, certificate generation, and configuration of OpenVPN.

Prerequisites

A VPS running Ubuntu/Debian
Root access to the server
OpenSSH access to the server

Installation

Copy the setup_openvpn.sh script to your server
Make the script executable:
```
chmod +x setup_openvpn.sh
```
Run the script as root:
```
sudo ./setup_openvpn.sh
```

What the Script Does

Updates the system
Installs OpenVPN and required packages
Sets up the PKI (Public Key Infrastructure)
Generates server certificates and keys
Configures the OpenVPN server
Sets up firewall rules
Creates a client certificate generation script

Generating Client Certificates

After the server is set up, you can generate client certificates using the provided script:

sudo /etc/openvpn/server/generate-client.sh <client-name>

This will create a client configuration file in /etc/openvpn/client/<client-name>.ovpn

Connecting to the VPN

Copy the generated .ovpn file from /etc/openvpn/client/ to your local machine
Install OpenVPN client on your local machine
Import the .ovpn file into your OpenVPN client
Connect to the VPN

Security Notes

The script uses UDP port 1194 (default OpenVPN port)
AES-256-CBC encryption is used
The server uses Google DNS (8.8.8.8 and 8.8.4.4)
The VPN subnet is set to 10.8.0.0/24
The script enables IP forwarding and configures the firewall

Troubleshooting

If you encounter any issues:

Check the OpenVPN server logs:
```
sudo journalctl -u openvpn@server
```
Verify the firewall rules:
```
sudo ufw status
```
Check if the OpenVPN service is running:
```
sudo systemctl status openvpn@server
```

Important Files

Server configuration: /etc/openvpn/server/server.conf
Client configurations: /etc/openvpn/client/
Server certificates: /etc/openvpn/server/
Client certificate generation script: /etc/openvpn/server/generate-client.sh